BLOOD AND LYMPH
UKMLA Conditions Categorised by Body System
,Abnormal Blood Film
Microscopic examination of a stained peripheral blood smear, assessing red cell, white cell and platelet morphology. Specific
patterns point strongly toward an underlying haematological or systemic diagnosis.
Key clinical features
• Requested when FBC results are abnormal or unexplained, or when a specific diagnosis (e.g. haemolysis, leukaemia,
hyposplenism) is suspected clinically.
• Assesses red cell size/shape/colour, white cell numbers and morphology, and platelet number/clumping.
• Key patterns and their associations are summarised below.
Figure 1: Common blood film findings and what they suggest.
Investigations
• Repeat FBC to confirm any abnormality is not a sampling artefact (e.g. platelet clumping causing false thrombocytopenia).
• Direct further work-up based on the pattern seen — e.g. haemolysis screen for schistocytes/spherocytes, bone marrow biopsy for
blast cells.
• Correlate findings with clinical context and other blood results (renal function, LDH, bilirubin, inflammatory markers).
Treatment and management
• Management is directed entirely by the underlying cause identified — the film itself is a diagnostic tool, not a disease.
Complications
• Missed or delayed diagnosis if a film is not requested when clinically indicated (e.g. new cytopenia, unexplained anaemia).
, Anaemia
A reduced haemoglobin concentration below the normal range for age and sex. Classified by mean cell volume (MCV) as microcytic,
normocytic, or macrocytic, which narrows the differential diagnosis.
Key clinical features
• Fatigue, lethargy, dyspnoea on exertion, palpitations, pallor (skin, conjunctivae, nail beds).
• Microcytic: usually iron deficiency (koilonychia, pica, angular stomatitis) or thalassaemia trait.
• Macrocytic: B12/folate deficiency (glossitis, peripheral neuropathy if B12) or alcohol excess/liver disease.
• Normocytic: anaemia of chronic disease, renal failure, acute blood loss, or early mixed deficiency.
• Haemolytic causes: jaundice, dark urine, splenomegaly.
Investigations
• FBC and blood film — first-line, guides further testing by MCV.
• Reticulocyte count — raised in haemolysis/blood loss, low in marrow failure/deficiency.
• Ferritin and iron studies (microcytic); B12 and folate levels (macrocytic).
• Haemolysis screen if suspected: LDH, haptoglobin, unconjugated bilirubin, direct antiglobulin (Coombs) test.
• Haemoglobin electrophoresis if haemoglobinopathy suspected.
Treatment and management
• Treat the underlying cause — e.g. investigate and manage a source of GI bleeding in iron deficiency.
• Oral iron replacement (or IV iron if intolerant/malabsorption/ongoing losses).
• B12/folate replacement (check B12 status before starting folate alone, to avoid precipitating subacute combined degeneration of
the cord).
• Blood transfusion if severe, symptomatic, or haemodynamically significant.
Complications
• High-output cardiac failure with severe/chronic anaemia
• Worsening of comorbid ischaemic heart disease
• Complications of transfusion (see Transfusion reactions)
UKMLA Conditions Categorised by Body System
,Abnormal Blood Film
Microscopic examination of a stained peripheral blood smear, assessing red cell, white cell and platelet morphology. Specific
patterns point strongly toward an underlying haematological or systemic diagnosis.
Key clinical features
• Requested when FBC results are abnormal or unexplained, or when a specific diagnosis (e.g. haemolysis, leukaemia,
hyposplenism) is suspected clinically.
• Assesses red cell size/shape/colour, white cell numbers and morphology, and platelet number/clumping.
• Key patterns and their associations are summarised below.
Figure 1: Common blood film findings and what they suggest.
Investigations
• Repeat FBC to confirm any abnormality is not a sampling artefact (e.g. platelet clumping causing false thrombocytopenia).
• Direct further work-up based on the pattern seen — e.g. haemolysis screen for schistocytes/spherocytes, bone marrow biopsy for
blast cells.
• Correlate findings with clinical context and other blood results (renal function, LDH, bilirubin, inflammatory markers).
Treatment and management
• Management is directed entirely by the underlying cause identified — the film itself is a diagnostic tool, not a disease.
Complications
• Missed or delayed diagnosis if a film is not requested when clinically indicated (e.g. new cytopenia, unexplained anaemia).
, Anaemia
A reduced haemoglobin concentration below the normal range for age and sex. Classified by mean cell volume (MCV) as microcytic,
normocytic, or macrocytic, which narrows the differential diagnosis.
Key clinical features
• Fatigue, lethargy, dyspnoea on exertion, palpitations, pallor (skin, conjunctivae, nail beds).
• Microcytic: usually iron deficiency (koilonychia, pica, angular stomatitis) or thalassaemia trait.
• Macrocytic: B12/folate deficiency (glossitis, peripheral neuropathy if B12) or alcohol excess/liver disease.
• Normocytic: anaemia of chronic disease, renal failure, acute blood loss, or early mixed deficiency.
• Haemolytic causes: jaundice, dark urine, splenomegaly.
Investigations
• FBC and blood film — first-line, guides further testing by MCV.
• Reticulocyte count — raised in haemolysis/blood loss, low in marrow failure/deficiency.
• Ferritin and iron studies (microcytic); B12 and folate levels (macrocytic).
• Haemolysis screen if suspected: LDH, haptoglobin, unconjugated bilirubin, direct antiglobulin (Coombs) test.
• Haemoglobin electrophoresis if haemoglobinopathy suspected.
Treatment and management
• Treat the underlying cause — e.g. investigate and manage a source of GI bleeding in iron deficiency.
• Oral iron replacement (or IV iron if intolerant/malabsorption/ongoing losses).
• B12/folate replacement (check B12 status before starting folate alone, to avoid precipitating subacute combined degeneration of
the cord).
• Blood transfusion if severe, symptomatic, or haemodynamically significant.
Complications
• High-output cardiac failure with severe/chronic anaemia
• Worsening of comorbid ischaemic heart disease
• Complications of transfusion (see Transfusion reactions)
